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I I I I I I I I I I I I I I I I I I I DOLORES RIVER FISH SAMPLES A Site on the Dolores River was sampled for the first time in 2000. A fairly equal number of fish over and under 15 em were collected at the site. The most common fish over 15cm sampled was round tail chub at 55% (Table 6). Flannelmouth sucker was 16% and bluehead sucker was only 2%. The most common non-native fish was channel catfish at 16%. The most common fish under 15 em on the Dolores River was also the roundtail chub (48%), followed by speckled dace (34%) (Table 6). Native fish were 87% of the small fish sample. The most common nonnative fish <15 em was green sunfish. The Dolores is the only site sample that contained channel catfish <15 cm. A quick comparison between data from this study and Valdez (1992), data from 1990 and 1991, shows fewer flannel mouth sucker and more roundtai( chub now. The data extracted from Valdez (1992) in Table 6 is not sorted by size groups, but an effort will be made to provide a more direct comparison between these earlier and current collections in the final report. Lenf!1h Frequencv (YamTJa. Colorado and D%res Rivers) Length frequency histograms for each station sampled in 1998 and 1999 are available in last years progress report (Anderson and Stewart 2000). Refer to the 2000 report to compare prior years to this year's data given in the Appendix. The length frequency histograms for bluehead sucker were very similar between years (1998, 1999 and 2000) at the Sevens and Duffy sites on the Yampa River. As was observed in earlier years, bluehead sucker under 34 em were rare at Duffy in 2000 (Figure AI), but smaller bluehead down to 28 cm were common at both Sevens (Figure AZ) and Lily Park (Figure A3). All bluehead on the Dolores River were less than 28 em (Figure A4). On the Colorado River the size spread of 27